This invention relates to an apparatus designed to exercise the skeletal muscles employing the forces of gravity, momentum and counterbalance.
It is well known that there are two aspects of muscular development--isotonic and isometric. Isotonic is a reference to tonal quality, smooth operation and range of operation. Isometric is a reference to size and the ability to resist movement of the musculature. Both aspects are equally valuable and, ideally, should occur in conjunction with each other. This can be accomplished by attempting to control the effect of a moving weight at the end of a longitudinal arm. As the weight comes to the end of a swing, the muscles of the body stop the movement of the weight to protect the body from injury. The inertial effects cause the weight to tend to continue a swing in a particular direction. In resisting this motion, the muscles are stretched a bit further than normal. As long as this overswing is fully controlled, it can be used to progressively increase the muscular range. The muscles may also be used to hold the weight at the end of the maximum swing. The strain of doing this will cause the muscles to take on a new "set".
In the prior art, U.S. Pat. No. 3,094,324 to Shingleton discloses an exerciser with a central shaft, arm members for gripping the device and a weight attached to the central shaft near the bottom thereof. However, the positioning of the arm members and the general configuration of this device make it difficult to carry out many useful exercises.
U.S. Pat. No. 3,290,044 to Krodsen discloses a mobile exercise bar. It is, however, not adapted for use as a swinging weight.
U.S. Pat. No. 3,468,534 to Donato shows an exercise bar having revolvable arms.
Related exercising devices are shown, for example, in U.S. Pat. Nos. 2,909,371 to Alcover; 3,228,683 to Leteff; 3,531,111 to Shafer and 4,023,796 to Kusmer.
These prior art inventions do not disclose a relatively simple exercising device adapted for convenient use in a considerable number of different exercises employing a swinging weight to accomplish muscular development.